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SHOGUN
4.1.0
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This class can be used to convert a document collection contained in a CStringFeatures<char> object where each document is stored as a single vector into a hashed Bag-of-Words representation. Like in the standard Bag-of-Words representation, this class considers each document as a collection of tokens, which are then hashed into a new feature space of a specified dimension. This class is very flexible and allows the user to specify the tokenizer used to tokenize each document, specify whether the results should be normalized with regards to the sqrt of the document size, as well as to specify whether he wants to combine different tokens. The latter implements a k-skip n-grams approach, meaning that you can combine up to n tokens, while skipping up to k. Eg. for the tokens ["a", "b", "c", "d"], with n_grams = 2 and skips = 2, one would get the following combinations : ["a", "ab", "ac" (skipped 1), "ad" (skipped 2), "b", "bc", "bd" (skipped 1), "c", "cd", "d"].
在文件 HashedDocConverter.h 第 39 行定义.
Public 成员函数 | |
| CHashedDocConverter () | |
| CHashedDocConverter (int32_t hash_bits, bool normalize=false, int32_t n_grams=1, int32_t skips=0) | |
| CHashedDocConverter (CTokenizer *tzer, int32_t hash_bits, bool normalize=false, int32_t n_grams=1, int32_t skips=0) | |
| virtual | ~CHashedDocConverter () |
| virtual CFeatures * | apply (CFeatures *features) |
| SGSparseVector< float64_t > | apply (SGVector< char > document) |
| virtual const char * | get_name () const |
| void | set_normalization (bool normalize) |
| void | set_k_skip_n_grams (int32_t k, int32_t n) |
| virtual CSGObject * | shallow_copy () const |
| virtual CSGObject * | deep_copy () const |
| virtual bool | is_generic (EPrimitiveType *generic) const |
| template<class T > | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| template<> | |
| void | set_generic () |
| void | unset_generic () |
| virtual void | print_serializable (const char *prefix="") |
| virtual bool | save_serializable (CSerializableFile *file, const char *prefix="") |
| virtual bool | load_serializable (CSerializableFile *file, const char *prefix="") |
| void | set_global_io (SGIO *io) |
| SGIO * | get_global_io () |
| void | set_global_parallel (Parallel *parallel) |
| Parallel * | get_global_parallel () |
| void | set_global_version (Version *version) |
| Version * | get_global_version () |
| SGStringList< char > | get_modelsel_names () |
| void | print_modsel_params () |
| char * | get_modsel_param_descr (const char *param_name) |
| index_t | get_modsel_param_index (const char *param_name) |
| void | build_gradient_parameter_dictionary (CMap< TParameter *, CSGObject * > *dict) |
| virtual void | update_parameter_hash () |
| virtual bool | parameter_hash_changed () |
| virtual bool | equals (CSGObject *other, float64_t accuracy=0.0, bool tolerant=false) |
| virtual CSGObject * | clone () |
静态 Public 成员函数 | |
| static index_t | generate_ngram_hashes (SGVector< uint32_t > &hashes, index_t hashes_start, index_t len, SGVector< index_t > &ngram_hashes, int32_t num_bits, int32_t ngrams, int32_t tokens_to_skip) |
Public 属性 | |
| SGIO * | io |
| Parallel * | parallel |
| Version * | version |
| Parameter * | m_parameters |
| Parameter * | m_model_selection_parameters |
| Parameter * | m_gradient_parameters |
| uint32_t | m_hash |
Protected 成员函数 | |
| void | init (CTokenizer *tzer, int32_t d, bool normalize, int32_t n_grams, int32_t skips) |
| int32_t | count_distinct_indices (CDynamicArray< uint32_t > &hashed_indices) |
| SGSparseVector< float64_t > | create_hashed_representation (CDynamicArray< uint32_t > &hashed_indices) |
| virtual void | load_serializable_pre () throw (ShogunException) |
| virtual void | load_serializable_post () throw (ShogunException) |
| virtual void | save_serializable_pre () throw (ShogunException) |
| virtual void | save_serializable_post () throw (ShogunException) |
Protected 属性 | |
| int32_t | num_bits |
| CTokenizer * | tokenizer |
| bool | should_normalize |
| int32_t | ngrams |
| int32_t | tokens_to_skip |
Default constructor
在文件 HashedDocConverter.cpp 第 23 行定义.
| CHashedDocConverter | ( | int32_t | hash_bits, |
| bool | normalize = false, |
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| int32_t | n_grams = 1, |
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| int32_t | skips = 0 |
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| ) |
Constructor Creates tokens on whitespace
| hash_bits | the number of bits of the hash. Means a dimension of size 2^(hash_bits). |
| normalize | whether to normalize vectors or not |
| n_grams | the max number of tokens to consider when combining tokens |
| skips | the max number of tokens to skip when combining tokens |
在文件 HashedDocConverter.cpp 第 28 行定义.
| CHashedDocConverter | ( | CTokenizer * | tzer, |
| int32_t | hash_bits, | ||
| bool | normalize = false, |
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| int32_t | n_grams = 1, |
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| int32_t | skips = 0 |
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| ) |
Constructor
| tzer | the tokenizer to use |
| hash_bits | the number of bits of the hash. Means a dimension of size 2^(hash_bits). |
| normalize | whether to normalize vectors or not |
| n_grams | the max number of tokens to consider when combining tokens |
| skips | the max number of tokens to skip when combining tokens |
在文件 HashedDocConverter.cpp 第 34 行定义.
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virtual |
Destructor
在文件 HashedDocConverter.cpp 第 40 行定义.
Hashes each string contained in features
| features | the strings to be hashed. Must be an instance of CStringFeatures. |
实现了 CConverter.
在文件 HashedDocConverter.cpp 第 81 行定义.
| SGSparseVector< float64_t > apply | ( | SGVector< char > | document | ) |
Hashes the tokens contained in document
| document | the char vector to tokenize and hash |
the array will contain all the hashes generated from the tokens
this vector will maintain the current n+k active tokens in a circular manner
the combinations generated from the current active tokens will be stored here to avoid creating new objects
Reading n+s-1 tokens
Reading token and storing index to hashed_indices
For remaining combinations
Normalizing vector
在文件 HashedDocConverter.cpp 第 101 行定义.
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inherited |
Builds a dictionary of all parameters in SGObject as well of those of SGObjects that are parameters of this object. Dictionary maps parameters to the objects that own them.
| dict | dictionary of parameters to be built. |
在文件 SGObject.cpp 第 597 行定义.
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virtualinherited |
Creates a clone of the current object. This is done via recursively traversing all parameters, which corresponds to a deep copy. Calling equals on the cloned object always returns true although none of the memory of both objects overlaps.
在文件 SGObject.cpp 第 714 行定义.
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protected |
This method takes a dynamic array as an argument, sorts it and returns the number of the distinct elements(indices here) in the array.
| hashed_indices | the array to sort and count elements |
Counting nnz features
在文件 HashedDocConverter.cpp 第 228 行定义.
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protected |
This method takes the dynamic array containing all the hashed indices of a document and returns a compact sparse representation with each index found and with the count of such index
| hashed_indices | the array containing the hashed indices |
在文件 HashedDocConverter.cpp 第 184 行定义.
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virtualinherited |
A deep copy. All the instance variables will also be copied.
在文件 SGObject.cpp 第 198 行定义.
Recursively compares the current SGObject to another one. Compares all registered numerical parameters, recursion upon complex (SGObject) parameters. Does not compare pointers!
May be overwritten but please do with care! Should not be necessary in most cases.
| other | object to compare with |
| accuracy | accuracy to use for comparison (optional) |
| tolerant | allows linient check on float equality (within accuracy) |
在文件 SGObject.cpp 第 618 行定义.
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static |
Generates all the k-skip n-grams combinations for the pre-hashed tokens in hashes, starting from hashes[hashes_start] and going up to hashes[1+len] in a circular manner. The generated tokens (maximun (n-1)(k+1)+1) are stored in ngram_hashes. The number of created tokens is returned in case fewer tokens are generated (due to a smaller len than the size of hashes). See class description for more information on k-skip n-grams.
| hashes | the hashes of the tokens to combine as k-skip n-grams |
| hashes_start | the index in hashes to consider as the starting point |
| len | the maximum allowed number of tokens to reach in a circular manner, starting from hashes_start |
| ngram_hashes | the vector where to store the generated hashes. Must have been created to be able to store at most (n-1)(k+1)+1 tokens. |
| num_bits | the dimension in which to limit the hashed indices (means a dimension of size 2^num_bits) |
| ngrams | the n in k-skip n-grams or the max number of tokens to combine |
| tokens_to_skip | the k in k-skip n-grams or the max number of tokens to skip when combining |
在文件 HashedDocConverter.cpp 第 205 行定义.
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在文件 SGObject.cpp 第 498 行定义.
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Returns description of a given parameter string, if it exists. SG_ERROR otherwise
| param_name | name of the parameter |
在文件 SGObject.cpp 第 522 行定义.
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Returns index of model selection parameter with provided index
| param_name | name of model selection parameter |
在文件 SGObject.cpp 第 535 行定义.
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init
在文件 HashedDocConverter.cpp 第 45 行定义.
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virtualinherited |
If the SGSerializable is a class template then TRUE will be returned and GENERIC is set to the type of the generic.
| generic | set to the type of the generic if returning TRUE |
在文件 SGObject.cpp 第 296 行定义.
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virtualinherited |
Load this object from file. If it will fail (returning FALSE) then this object will contain inconsistent data and should not be used!
| file | where to load from |
| prefix | prefix for members |
在文件 SGObject.cpp 第 369 行定义.
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Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_POST is called.
| ShogunException | will be thrown if an error occurs. |
被 CKernel, CWeightedDegreePositionStringKernel, CList, CAlphabet, CLinearHMM, CGaussianKernel, CInverseMultiQuadricKernel, CCircularKernel , 以及 CExponentialKernel 重载.
在文件 SGObject.cpp 第 426 行定义.
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Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::LOAD_SERIALIZABLE_PRE is called.
| ShogunException | will be thrown if an error occurs. |
被 CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool > , 以及 CDynamicObjectArray 重载.
在文件 SGObject.cpp 第 421 行定义.
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在文件 SGObject.cpp 第 262 行定义.
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prints all parameter registered for model selection and their type
在文件 SGObject.cpp 第 474 行定义.
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Save this object to file.
| file | where to save the object; will be closed during returning if PREFIX is an empty string. |
| prefix | prefix for members |
在文件 SGObject.cpp 第 314 行定义.
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Can (optionally) be overridden to post-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_POST is called.
| ShogunException | will be thrown if an error occurs. |
被 CKernel 重载.
在文件 SGObject.cpp 第 436 行定义.
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Can (optionally) be overridden to pre-initialize some member variables which are not PARAMETER::ADD'ed. Make sure that at first the overridden method BASE_CLASS::SAVE_SERIALIZABLE_PRE is called.
| ShogunException | will be thrown if an error occurs. |
被 CKernel, CDynamicArray< T >, CDynamicArray< float64_t >, CDynamicArray< float32_t >, CDynamicArray< int32_t >, CDynamicArray< char >, CDynamicArray< bool > , 以及 CDynamicObjectArray 重载.
在文件 SGObject.cpp 第 431 行定义.
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在文件 SGObject.cpp 第 41 行定义.
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在文件 SGObject.cpp 第 46 行定义.
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在文件 SGObject.cpp 第 51 行定义.
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在文件 SGObject.cpp 第 56 行定义.
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在文件 SGObject.cpp 第 61 行定义.
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在文件 SGObject.cpp 第 66 行定义.
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在文件 SGObject.cpp 第 71 行定义.
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在文件 SGObject.cpp 第 76 行定义.
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在文件 SGObject.cpp 第 81 行定义.
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在文件 SGObject.cpp 第 86 行定义.
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在文件 SGObject.cpp 第 91 行定义.
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在文件 SGObject.cpp 第 96 行定义.
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在文件 SGObject.cpp 第 101 行定义.
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在文件 SGObject.cpp 第 106 行定义.
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在文件 SGObject.cpp 第 111 行定义.
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set generic type to T
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| void set_k_skip_n_grams | ( | int32_t | k, |
| int32_t | n | ||
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Method used to specify the parameters for the quadratic approach of k-skip n-grams. See class description for more details and an example.
| k | the max number of allowed skips |
| n | the max number of tokens to combine |
在文件 HashedDocConverter.cpp 第 251 行定义.
| void set_normalization | ( | bool | normalize | ) |
specify whether hashed vector should be normalized or not
| normalize | whether to normalize |
在文件 HashedDocConverter.cpp 第 246 行定义.
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virtualinherited |
A shallow copy. All the SGObject instance variables will be simply assigned and SG_REF-ed.
被 CGaussianKernel 重载.
在文件 SGObject.cpp 第 192 行定义.
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unset generic type
this has to be called in classes specializing a template class
在文件 SGObject.cpp 第 303 行定义.
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Updates the hash of current parameter combination
在文件 SGObject.cpp 第 248 行定义.
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io
在文件 SGObject.h 第 369 行定义.
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parameters wrt which we can compute gradients
在文件 SGObject.h 第 384 行定义.
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Hash of parameter values
在文件 SGObject.h 第 387 行定义.
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model selection parameters
在文件 SGObject.h 第 381 行定义.
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parameters
在文件 SGObject.h 第 378 行定义.
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the number of consecutives tokens for quadratic
在文件 HashedDocConverter.h 第 154 行定义.
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the number of bits of the hash
在文件 HashedDocConverter.h 第 145 行定义.
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parallel
在文件 SGObject.h 第 372 行定义.
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whether to normalize or not
在文件 HashedDocConverter.h 第 151 行定义.
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the tokenizer
在文件 HashedDocConverter.h 第 148 行定义.
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the number of tokens to skip
在文件 HashedDocConverter.h 第 157 行定义.
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version
在文件 SGObject.h 第 375 行定义.
